noun
nut
A person considered irrational or eccentric, in insulting slang.
He calls his neighbor a nut for talking to trees.
Etymology
Nut became slang for the head and then for a person considered strange or unsound in judgment. The person-name is a figurative extension and can be insulting.
More examples
- They dismiss her as a nut instead of hearing her ideas.
- The neighbors think we're a couple of nuts.
- My sister is a history nut who visits every battlefield.
Forms
nut · nuts
nutty adjective — Eccentric or irrational, in informal speech.